Whatdidyoufndout: Alt Attribute & Search engine optimization

SEO Optimization images is becoming more and more important in SEO (Search Engine Optimization) for websites. The ALT attribute is really a critical step that is often overlooked. This can be a lost chance of better rankings.

In Google's webmaster guidelines, they advise the use of alternative text for the images on your site:

Images:. Make use of the alt attribute to provide descriptive text. Additionally, we recommend using a human-readable caption and descriptive text round the image.

Why would they ask us to do that? The answer is easy, really; search engines like google have a similar problem as blind users. They can't begin to see the images.

Many webmasters and inexperienced or unethical SEOs abuse the use of this attribute, trying to stuff it with keywords, hoping to achieve a certain keyword density, which is not as relevant for rankings now since it was previously.

On the contrary, high keyword density can, on some search engines like google, trigger spam filters, which may create a penalty for your site's ranking. Even without this type of penalty, your site's rankings will not take advantage of this plan.
This method also puts persons who use screen readers in a greater disadvantage. Screen readers are software-based tools that really read aloud the contents of what is displayed on the screen. In browsing the web, the alt features of images are read aloud too.

Imagine hearing a paragraph of text that is followed by repetitions of numerous keywords. The page will be not even close to accessible, and, to put it bluntly, will be found quite annoying.
What is an Alt attribute?

An ALT attribute shouldn't be used as a description or perhaps a label to have an image, though many people utilize it for the reason that fashion. Though it may appear natural to assume that alternate text is really a label or perhaps a description, it is not!

What used within an image's alt attribute ought to be its text equivalent and convey the same information or serve exactly the same purpose that the image would.

The thing is to supply the same functional information that the visual user would see. The alt attribute text should function as a "stand in" in the event that the image itself is not available. Ask yourself this question: If you were to replace the image with the text, would most users receive the same basic information, and would it generate the same response?
Some examples:

Some SEO Optimization Tips

If your search button is really a magnifier or binoculars its alt text ought to be 'search' or 'find' not 'magnifying glass' or 'binoculars'.

If the image is meant to convey the literal items in the look, a description is appropriate.

If it is meant to convey data, then that data is what is appropriate.

If it's designed to convey using a function, then the function itself is what should be used.

Some Alt Attribute Guidelines:

Always add alt attributes to images. Alt is mandatory for accessibility as well as for valid XHTML.

For images that play merely a decorative role within the page, use an empty alt (i.e. alt="") or a CSS background image to ensure that reading browsers do not bother users by uttering things like "spacer image".

Keep in mind that it is the function of the image we are trying to convey. For instance; any button images should not range from the word "button" in the alt text. They should emphasize the action performed by the button.

Alt text should be determined by context. The same image in a different context may need drastically different alt text.

Attempt to flow alt text with the rest of the text because that is how it is going to be read with adaptive technologies like screen readers. Someone hearing your page should hardly be aware that a graphic image is there.
Please remember that utilizing an alt attribute for each image is needed to satisfy the minimum WAI requirements, that are used as the benchmark for accessibility laws in UK and also the rest of Europe. Also, they are necessary to meet "Section 508" accessibility requirements in america.

It is useful to categorize non-text content into three levels:

Eye-Candy
Mood-Setting
Content and Function

I. Eye-Candy

Eye-Candy are things that serve no purpose apart from to make a site visually appealing/attractive and (oftentimes) fulfill the marketing departments. There isn't any content value (though there might be value to a sighted user).

Never alt-ify eye-candy unless there is something there that will boost the usability from the site for someone utilizing a non-visual user agent. Make use of a null alt attribute or background images in CSS for eye-candy.

II. Mood-Setting

This is actually the middle layer of graphics which may serve to set the atmosphere or set happens as it were. These graphics aren't direct content and could 't be considered essential, but they are important in they help frame what is going on.

Try to alt-ify the 2nd group as is sensible and it is relevant. There may be instances when doing so may be annoying or detrimental to other users. Then avoid it.

For example; Alt text that's just like adjacent text is unnecessary, as well as an irritant to screen reader users. I suggest alt="" or background CSS images in such cases. But sometimes, it's vital that you understand this content in there for all users.

Most times it depends on context. Exactly the same image in a different context may require drastically different alt text. Obviously, content ought to always be fully available. The way you go in this example is a judgment call.

III. Content and Function

This is where the image may be the actual content. Always alt-ify content and functional images. Title and long description attributes can also be in order.
The main reason many authors can't understand why their alt text isn't working is they don't know why the images are there. You have to figured out exactly what function an image serves. Consider what it is concerning the image that's vital that you the page's intended audience.

Every graphic has a reason for standing on that page: since it either improves the theme/ mood/ atmosphere or it is advisable to what the page is trying to describe. Knowing what the look is for makes alt text simpler to write. And practice writing them definitely helps.
A method to look into the usefulness of alternative text is to imagine reading the page on the phone to someone. What would you say when encountering a particular image to make the page understandable to the listener?

Aside from the alt attribute you've got a couple more tools available for images.
First, in level of descriptiveness title is in between alt and longdesc. It adds useful information and may add flavor. The title attribute is optionally rendered through the user agent. Remember they're invisible and never shown as a "tooltip" when focus is received through the keyboard. (So much for device independence). So make use of the title attribute just for advisory information.
Second, the longdesc attribute points to the URL of a full description of the image. When the information contained in an image is important towards the meaning of the page (i.e. some important content would be lost if the image was removed), a longer description compared to "alt" attribute can reasonably display ought to be used. It may provide for rich, expressive documentation of the visual image.

It should be used when alt and title are insufficient to embody the visual qualities of the image. As Clark [1] states, "A longdesc is a long description of the image...The goal is to use any length of description necessary to impart the facts of the graphic.

It would not be remiss to hope that the long description conjures an image - the look - in the mind's eye, an analogy that is true even for the totally blind."

Although the alt attribute is mandatory for web accessibility as well as for valid (X)HTML, not all images need alternative text, long descriptions, or titles.

Oftentimes, you're best just going with your gut instinct -- if it's not essential to incorporate it, and if you don't have a strong urge to get it done, don't add that longdesc.

However, if it's necessary for the whole page to work, then you've to include the alt text (or title or longdesc).

What's necessary and what's not depends a lot on the function of the image and it is context on the page.

Exactly the same image may require alt text (or title or longdesc) in a single spot, but not in another. If the image provides simply no content or functional information alt="" or background CSS images might be appropriate to use. But if the image provides content or adds functional information an alt will be required and maybe even a long description will be so as. In many cases this kind of thing is a judgement call.